猪瘟病毒感染性cDNA克隆的构建及其致病性

为了建立研究猪瘟病毒的技术平台，利用RT-PCR技术构建了猪瘟病毒中国石门株(Shimen)的全长有感染性cDNA克隆pT7SM。通过体外转录线性化的pT7SM并将转录的RNA转染至PK-15细胞中，获得了猪瘟病毒粒子。再用间接免疫荧光法测定了其生长曲线，通过电镜观察到重组病毒呈球形，具有囊膜结构。进一步把获得的猪瘟病毒粒子感染非免疫实验猪，结果子代病毒与石门株类似，对非免疫实验猪有强烈的致病性，证明该全长cDNA克隆可靠稳定，忠实地保留了石门株病毒的感染性和致病特征。由此为进一步探讨猪瘟病毒的致弱机制及病毒与机体相互作用的机制打下了良好的基础。

Construction and Pathogenicity of Infectious cDNA Clone of Classical Swine Fever Virus (CSFV)

To establish a research platform for study of CSFV,we constructed the infectious full-length cDNA clone(pT7SM)of CSFV strain Shimen by RT-PCR.After transfection of in vitro-transcribed RNA derived from pT7SM,infectious CSFV which named vT7SM was recovered from PK-15 cell.vT7SM was titrated by immunofluorescence assay and detected by electron microscope.It was proved that vT7SM had infectivity and replicative ability as its parent strain.We also tested the infectivity of vT7SM in animal and demonstrated that vT7SM had the equivalent infectivity and virulence that undistinguished from the wild-type strain Shimen.Thus,we had constructed a reliable full-length cDNA clone which is valuable for further research such as the mechanism of CSFV's attenuation and the interaction between CSFV and its native host.